Coal mining apparatus



April 18, 1933. N. D. LEVIN COAL MINING APPARATUS Fild Oct. 16. 1929 00gb 0 n G QQ 3 5a 7 O I O L a L i I 3 sheets-sheet 1 mmvrofi M15 0, L EV//V A ril 18, 1933. N. D. LEVIN COAL MINING APPARATUS Filed 001:. 16, 1929 5 Sheets-Sheet 2 z flflfllnmmwwrllflil W bu X I I E.

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COAL MINING AIPARATUS Filed Oct. 16, 1929 3 Sheets-Sheet 5 mun IN I/EN 701?. lV/ZJ 17. LEVI/Y.

Patented Apr. 18, 1933' UNITED STATES PATENT omen Y NILS n. LEVIN, or coLU Bns, OHIO, ASSIGNOR TO THE JEFFREY- iunnnrnotroitiito COMPANY, OF COLUMBUS, oriio, A CORPORATION oFoHIov r f COAL MINING APPARATUS Application filed October 16, 1929. Serial No. 400,063.

This invention relates to new and useful improvements in mining machines.

An important object of the invention is to provide an improved elevating mechanism for the coal cutting instrumentality mounted on the truck frame.

Another important object of the inven-' tion is to provide an elevating mechanism.

of the above character which dispenses with the necessity of using different size pedestals to attain the required elevations of the coal cutting instrumentality, said mechanism including a sectional pedestal comprising a plurality of telescopic floating guides which serve in maintaining the coal cutting instrumentality in a stateof rigidness heretofore found impossible with. the;

elevating mechanism heretofore employed. A still further object of the invention is to provide a coal mining machine elevating mechanism with a compound screw elevator thereby increasing the speed of vertical adjustments.

Other objects and advantages ofthe invention will become apparent during the r means for the elevating mechanism, as well as the means of locomotion of the mining truck.

Flgure 3 1s an enlarged vertical section through one of the improved elevating screw mechanisms taken along the line 33 of Figure 1.

Figure 4 is a similar section of the elevat ing screw mechanism with the mechanism extended to its full height.

Figure 5 is a transverse section taken through the mechanism on the line 55 of Figure 4.

Figure 6 is a transverse section taken through the elevating mechanism on the line 66 of Figure 3.

elevatlng Figure 7 is an enlarged section of the lower end of'one elevating mechanism illustrat ing the clutch-operator.

Figure 8 isa sectional viewofthe drive mechanism taken on line 8-8 of Figure 2.

Figure 9 is a sectional view taken along line 99 of Figure 18. I I I Figure. 10 is a diagrammatic view. of the gearing illustrated in Figure 8, and; 1

Figure 11' is amperspectiveview .of-the clutch shifting devices associated with the gearing illustrated in FiguresS and 9. Inthe present illustration of the invention; I have elected .to show the present invention as applied to an arcwall mining machine of the usualtype which is'po'wer. driven along track rails but it is to be understood thatthe invention may be applied to any type of mining machine. v p

Referrin now-mo-re, particularly to the drawings, the numeral 1 designates the main frame of a mining machine equipped with a pair ofaxles 2, .providedwithtraction wheels 3, drivenv from the usual electric motor 4 through power. devices 5 and sprocket chains 6 and 7. Suitablecontrol mechanisms are provided for controlling the electric motor and for clutching the axle.

drives to the'power devices, which will now be described.

Fixed to the forward axle 2- is a brake drum 60 which is encircledby a brakeband 61 connected by a toggle 62 and link 63 with a transverse shaft 64 mounted in suitable bearings upon the truck frame. 'To the shaft 64 is fixed a rocker arm 65 which is connected by a. rod 66 with the operating lever 67, of well-known design, adapted to be held in retracted position by the notched ratchet plate 68. By manipulationof the lever 67 tension may be applied to thebrake band 61 to exert a retarding force upon the brake drum 60 to resist rotation of the-axle 2, and by engagement of the operating lever 67 with the ratchet plate 68 thetension of the brake band may be maintained at the will of the operator. 7 f

Mounted upon the truck frame is the electric motor 4 which supplies'power for the propulsion of the carriage and for the acto an extension floor plate 72 which projects rearwardly of the truck frame to form a step upon which the operator may ride when the machine is traveling from one working place to another. This method of connecting the motor 1 with the worm shaft '69 affords a desirable flexibility between the; power ment with the spur gear 81.

units and permits the removal of either of these parts without disturbing the other. Formed upon the'worm shaft 69 1s a worm 7 3 which engages a worm wheel 7 4 mounted for free rotation upon the truck propelling .shaft 75 which extends transversely of the truck frame and is supported in journal bearings of the gear housing 70. The worm Wheel 7% is arranged to be connected with the truck propelling sl1aft 75 by a suitable friction clutch-76 arranged to be controlled 'by'the lever 77 adapted to rotary oscillatioAp about tlie'truck propelling shaft 75. bralre drum76' fixed to the truck propelling shaft 75 is encircled by a brake band 77, the'tension' of whichis controlled by movement of the'lever 77 which also controls the friction clutch 7 6. The arrangement of these parts is such that movement .of the lever 77 in one direction from its central neutral position causes the actuation of the clutch 76 to-drive the shaft 75, and movement of said lever in the. opposite direction,

from this central neutral position app-lies retarding force to the brake drum 76 to resis rotation of said shaft.

Attached to the extension floor plate 72 is a second gear casing 78 having suitable bearings, in which is supported an extension shaft 79 inlongitudinal alignment with the truck propelling shaft 75. The shafts 75 and 7 9 are operatively connected by a jaw clutch coupling 80 which affords ajdegree offlexibility very desirable in machinery of this class. Upon thisextensio-n shaft79 is mounted for free rotation relative theretoa spur gear 81 having an integral extension sleeve 82 towhich is'fixed a second gear 83.

Thegear 88 meshes with a spur gear 8 1,

fixed -to'one end of a countershaft 85, and to the other end of this countershaft 85 there is 'fixeda sprocketwheel 86 which-engages the truck propelling chain 6 to drive it. The countershaft 85is supported in parallelism with the extension shaft 79 in asleeve bear ing 87-which is suspended upon supporting pins 88 fixed to the gear housing in suchv manner that the sprocket wheel 86 may be moved longitudinally of the truck frame to adjust the tension of the driving chain 6. Two oppositely disposed set screws 89 are screw threaded in suitable apertures of the gear housing casting to afford means for effecting the adjustment of the sleeves 87 and the tensioning of the chain 6.

Fixed'tothe outer end of the extension shaft 79 is a spur pinion 90 in engagement with a spur gear 91 fixed to'the baclrgear shaft 92, suppo-rted in bearings of the gear housing and exten ing parallel with the shaft 79; 11 spur pinion 93 is slidably mounted upon the back gear shaft 92 and is rotatably connected therewith by a suitable feather key, and this pinion 93 is adapted to be moved into and out of engageh lovement of the pinion 93 is controlled by the shifting yoke 9fixed to the'shaft 95 which is longi-. tudinally slida-ble in apertures of the gear housing. Apin 96 projectinglaterally from the shaft 95affords a handle for the manipnlation of the pinion 93; *1 H Mounted upon'the extension shaft 79 is a bevel pinion 97 formed-integral. witha sleeve 98 which extends through the journal bearings 99 of the'gear housing, and upon the innerend ofthis sleeve 98 is formed a clutchineniber 100 adapted to engage with teeth formed on theouter face of the jaw clutch 101 when it is moved to its extreme right hand position. The bevel pinion 97 engages the bevel gear 102 loosely mounted upon the upper end of a vertical shaft 103 which is journaled in suitable bearings of the gear housing. "Removably mounted upon the shaft 103'- adjacentthe bevel gear 102 is a plate 10 1 having an aperture adapted for alignment with vertical aperture in the bevel gear'102 for the reception of a shear pin 105.." Beneath this removable plate 10% is a collar 106 turned integral with the shaft 103, and it also has an aperture for the reception of the lower end of the shear pin wher by the shear pin forms the connecpins may fall by gravity. onto the extension floor plate '72. To the vertical shaft 103 is fixed a sprocket wheel 108 which engages the driv ng chain'17 for the actuation of the elevating mechanisms hereinafter described.

Movement of the clutch 101 is controlled by theshifting yoke 109 attached to a shifting lever 110 which is pivotally sup-.

portedin the gear housing 78. A, controlling handle 111 attached tothe shifting lever 110 and positioned outside of the gear'housing 78 affords means for moving the clutch 101. 'A'spring-pressed dog-112 adapted-to engage either of' three' apertures in the ear housing casing, serves to hold the parts in either of three positions of adjustment.

clutch 101 is held out of engagement with I either the spur gear or the bevel gear.

Formed on the clutch shifting lever 110 is a crank arm 113 to which is connected the upwardly projecting interlocking bar 114: at the upper end of which is provided an aperture 115 through which projects the shaft 95. Formed in the shaft 95 is a notch 116 adapted to register with the interlocking bar 114 when the pinion93 is in its'position of disengagement from the gear 81. The shape and proportions of thisaperture 115 are such that the interlocking bar llt is held against vertical movement when the pinion 93 is in its position of engagement,

thereby preventing shifting of the clutch' 101 during such engagement, and the shaft 95 is held against longitudinal movement when the clutch 101 is in either of its po'- sitions of engagement, thereby preventing movement of the spur pinion 93 to engaged position when the clutch 101 is'in' either of its positions of engagement.

By the arrangement of parts above described, the power may be transmitted from the motor 4 through the truck propelling shaft 75, clutch 101, spur gears 83and 84, sprocket wheel 86, and chain 6 to propel the truck at a relatively high speed, or power may be transmittedthrough the truck propelling shaft 75, spur gears 90, 91, 93 and 81 to the spur gear'83, and through the gear 84, sprocket wheel 86 and chain 6, to propel the truck at a relatively low speed, and the interlocking mechanism is adapted to prevent the actuation of the gearing in antagonistic combinations.

It will also be obvious that movement of the clutch 101 to the right of Figure ,8

causes engagement of the clutchface 100 of the bevel gear 97 causing it to rotate with extension shaft 79 and operates bevel gear 102, and through the shear pin 105 drive means for the cutter chain are pro-j vided as well as controlsforstarting and stopping the same andsuitable means are also provided for turning the table 8-to move the kerf cutter from side to side of the machine in an are, as well as for locking the turntable in any desired .positionto retain the kerf cutting arm 10 in the desired angular ext'ensionfrom the mining machine to perform coal mining operations.

In order to cut kerfs in veins of coal at different elevations from the mine floor, it is necessary to provide an elevating mechanism for the support of the coal mining instrumentality and heretofore this has been accomplished by placing three single screw elevating mechanisms between the mining machine frame and the support for the coal cutting instrumentality. cutting mechanism substantiallyrigid during-mining operations different size pedestals had to be employed for different eleva-- To hold the coal.

'tions of the coal'cutting mechanism; In

order to provide for a wide range of vertical adjustments of the 'coal cutting [instrumentality without the necessity of requiring several different size'pedestal's, the present improved elev'atingfmechanism has been devised and has been found to not only give increased speed of elevation but to add'substantial rigidity' in thesupport of the coal cutting mechanism" whenin operation.

This improved elevating mechanism ;con-

sists primarily of three compound screw mechanisms indicated in their entirety by the numeral 11 positioned upon the mining machine frame '1 at points. substantially equi-distant around the turntable 8, it being observed'thattwoof the elevatingdevices are arranged at the two forward cor ners of the mining machine and the third on the longitudinal center line of theframe'at the side of theturntable opposite the two forward elevating mechanisms. Asall of the elevating mechanisms are of the"sa me construction, and have the same mode of operation, a description of one will be given for all.

Each compound nism comprises a step bearing12bolted to the underside of the mining machine frame 1 and to each stepped bearing is bolted a longitudinally extensible pedestal indicated screw elevating mechain its entirety by the numeral 13. Mounted within the stepped: bearing is a bushing 14: forming a bearing for a-vertically disposed drive sleeve 15. Loosely mounted upon this sleeve is a sprocket wheel 16 operated by a sprocket chain 17 ,"as clearly shown in Figures 2 and 7, driven by the sprocket 108 forming 'a' part of the power transmission devices :5, This sprocket chain is trained about the sprockets 16of all three elevating mechanisms as shown for operating them. Clutch mechanisms to be hereinafter deend ot the sprocket more 5 fully described hereinafter.

' scribed are provided for each sprocket 16 Bolted to the upperside ofthe'mining machine frame is a nut pedestal 19 arranged concentric withthedrive sleeve 15 and above the same as shown to form a bearing for the'uppcr' endof the same. hisvnutlis equipped with left/hand threads to cooperatexwith the left hand threads provided upon the exterior of a screw sleeve 20 pro vided with diametrically opposed -longitudi--. nal grooves 21; in its exterior for cooperationwvithxthe drive sleeve 15 for rotating the screw sleeve 2O by means of a clutch collar 23 feathered to the drive sleeve '15, as at 24 and havinga clutch. face cooperating with a clutch face 25 provided on the upper 16,:assh0wn in Fig ure 7 a The screw sleeve 20 isalso equipped with internalright hand threads for the recep tion of a right hand screw v26 held against rotation by a collar 27 thereon having a non-circular reduced portion 28 fittingvwitlr' in a corresponding opening in the uppermost floating guide 29 ofthe pedestal 13. The threads of all three of these members are preferably of the same-pitch but in case a greater range and" speed adjustment is re quired, the pitch of the threads of screw 26 maybe made greater than that of the screw sleeve 20.. The upper end '30 of the screw 26 is reduced above the reduced portion 28 to extend through a sleeve 31 havingits lower end seated in a recess of the floating guide 29. This sleeve 31 is equipped with an external shoulder 32 against which seats oneend of a coil spring 33 the upper end of which abuts a washer 84 held upon the reduced end of the screw 26 by means of a nut 35. This nut maybe turned to adjust the tensionof the coil'spring 33 as required. This sleeve 31 extendsthrough an opening in a cup-shaped bracket 36 securedto the outer periphery of the ring "9 and it is to be noted that the sleeve-has a loose lit in this bracket so that when desired, only one compound screw mechanism may be operated to tilt the kerf cutter and supporting table'S, as hereinbefore mentioned.

The upper floating guide section 29 is provided with a pair of depending flanges 37 equipped with a pair of diametrically opposed depending fianges 38"for engagement with the inwardly extending flanges of a second floating pedestal section 39 within which the upper section 29xis tel-escoped. The section 39'is provided on its interior with a vertically disposed groove'40 in which a projection 41-o'f the bracket 36 operates when the elevating mechanism is lowered and the floating guides telescope asindica'ted in Figure 3. Upon elevation of the screw 26 andupperpedestal section 29; the latter willmove out of the section 39 and cause elevation of the latter by means: of lugs 42 of the section 29. engaging beneath stops 43 of the section 89, as illustrated inFigure4.

Therfioating section 89 of the pedestal is adapted to telescopically slide within a third floating substantially U-shaped rigid section 44 of the extensible pedestal and is provided with a block 45 removablysecuredthereto hymeans-cffa set screw 46 tooperate with, in; a vertically disposed groove 47 of section 44. The block45 slides upwardly of the groove 47 upon elevation of the section 39. until it is carried into engagement with the upper end of the groovewhen it causes elevationfof the section 44. When the elevating mechanism is lowered, the block 45 slides down the'groove 47 until it engages the lower end thereof, thereby causing descent of section 44. This latter section is equipped with an openingv 48 which is adapted to register with an opening 49 in a stationary pedestal isection 50 which is bolted to the stepped bearing; as hereinbefore stated,-

when the elevating mechanism is in its lowered position in order that the block 45 may be removed iand'nthe floatingsections of the pedestal.disassembled. I I

In order to limitthe outward movemen of the section 44 with respect to the lower-' most section 50, a shoulder 51 isprovided within the latterfor "engagement with a projection'52 carried at the lower end of section 44. T I 7 v r As shown most clearly in Figures 5 and 6, the three lowermost sections 50,- 44 and 39 of the extensiblepedestal mgr sub'stan-' tially rectangular or U-shap'e in cross-section withinturned flanges-'53 of eachsection embracing corresponding inturned flanges of the next uppermost section. V This construction, while permitting free sliding or telescoping movement 'of:= one section within the other, provides an extremely rigid extensible support whether the sections and this provides for the rigidunfaltering support of the coal mining instrumentality. As shown, lubricant-grooves are provided on the contacting surfaces of the "floating sectional'guides to insure thorough lubricai tion and easy sliding operations.

The two clutch members-23 of the two forward elevating'screws are each provided; as shown, inFigure 2, with a clutch shiftingmember 54 connected by a rocker 55 to a lever 56 extending along theside of the mining machine frame to the rear there of and'terminating on the upper side in a handle 57 which may be conveniently manipulated by-the operator for causingindependent or. simultaneous Operation of the two forward screw mechanisms to the exclusion of the third screw mechanism. The third screw elevating mechanism located alongv the center line'of the machineis provided with a similar independent clutch operating mechanism having .a clutch operating handle 58 vby which this mechanism may be independently controlled for causing individual elevation of this elevating mechanism to the exclusion of the other two elevating mechanisms for tilting the ker'f cutter arm 10 in a downward direction. WVhen either of the two screw elevating mechanisms at the forward end of the machine are operated to the exclusion of the othertwo elevating screws, the kerf cutting arm 10 is tilted upwardly at an incline, and. obviously when all three elevating mechanisms are operated in unison, the kerf cutting arm and its support will be adjusted vertically uniformly, in order that the kerf cuttingarm 10 may be raisedand lowered in a perfectly horizontal position. i

When the clutch collar 23 of any of the three screw mechanisms is lowered into engagement with the clutch face 25 of sprocket l6 and the latter is being rotated, the drive sleeve 15 is caused to rotate. is conveyed to the screw sleeve 20 through the gib keys 22, thereby causing the same to grow out of the pedestal nut 19 and simultaneously cause the exten sion of screw 26 from the screw sleeve'20 due to the fact that the screw 26 is prevented thread arrangement of the compound screw causes simultaneous extension of the screw sleeve 20 and screw 26. As the compound screw elongates in elevating the cutting mechanism support, the upper. floating guides or section 29 of the pedestal is elevated until its lugs 42 engage beneath the stops 43 of the second floating section 39, thereby causing movement of the same with the screw mechanism. Elevation of. this section 39 causes successiveelevation of the section 44 by reason of the block 45 engaging the upper end of groove 47 and section 44 may be elevated until its stop lug 52 con.- tacts with a shoulder 51' of the lower pedes tal section 50. In order to prevent serious damage tothe operating mechanism after the stop 52 engages the shoulders 5.1, the shear pin 105 will shear ofl', thereby preventing damage to the power devices and elevating mechanisms.

On downward movement of the elevating mechanism this shear pin will shear if the clutch mechanism is not disengaged when the collar 27 of screw 26 engagesthe upper end of screw sleeve 20, or incase of the'o'pmachine element is angled to its maximum This rotation limits, said pin will shear. and preventse rious damage. g

It is to be understood that various changes in the size,-;shape andfarrangement ofparts may be resorted towithout departing from the scope of the; appended claims.

i What I claim is:-...

l. The combination with I chine, acoal cutting device vertically and horizontally adjustable thereon; of self contained. power. means) for vertically adjusting said device and being subject to lateral thrusts imposed-by the cutting device, and a longitudinally, extensible pedestal ;asso-. ciatedwith. said power means .to brace the latter against: said lateral thrusts.-

2. The combination with amining machine, a support fora coal cutting device 1 a mining ma-S mounted-thereon, said s'upp'ort, including a moving the;same, and a longitudinallyexe tensib'le pedestal associated with said. screw.

3. The combination with a mining machine, a support for a coal cutting device moimtedthereon, said support including a vertically adjustable part for supporting a horizontally adjustable part; of a double action screw connected to said vertically adjustable part for moving the same, a longitudinally, extensible pedestal associated with saidscrew means. y

4. The ,comb1nat1on -w1th a m ning machine fr'ame,fa support for a coal cutting device vertically-adjustable thereon, a com: pound screw mounted on said, frame and loosely. connected to said supportfor vertically adjusting the latter, and a longitudinally extensible pedestal connecting said screw and frame and including means for preventing rotation of a section of said compound screw; I v

5. Thelcombination with a mining machine frame, a support for a Coalcu'tting device vertically adj ustable thereon, a compound screw mounted on said frame and loosely connected to "said support for vertic'ally adjusting the latter, and a longi-w tudinally extensible pedestal connecting said screw'and frame and including a non-rotary sliding section' 'conne'cted,with a section of said screw to prevent rotation thereof.

1 6. The {combination with a mining machine frame, a supportifor aucOal cutting. device vertically adjustable thereon, of a double action "screw mounted" on said frame and having a non-rotaryfs'ec'tion loosely dea pending from said support, and a longir tudinallyextensible telescopic pedestal c011 nected' tosaid nonrotary section and to said machine frame.

'7. The combination of amining machinei frame, a supportfor acoal cutting device vertically adjustable thereon, of a double action screw mounted on said frame and having a non-rotary screw section depending from said support, said section having a noncircular shoulder, and a longitudinally eX- tensible sectional pedestal having'a section supported on said shoulder and slidably associated with an adjacent section to prevent rotation of said screw section. I 8. The combination with a mining machine frame', a support for. a coal cutting device vertically adjustable :thereon; of a pedestal nut secured to said frame, a screw sleeve operating through said nut and having an internal thread, a non-'rotaryscrew threaded into said sleeve and connected to said support, a rotary sleeve-embracing said screw sleeve and splined thereto, and means for actuating said rotary sleeve.

9. The combination with a mining machine frame, a support for a coal cutting device vertically adjustable. thereon; of a nut secured to said frame, ascrew sleeve operating through said nut'and having an internal thread, a non-rotary screw threaded into said sleeve and connected to said sup-' port, a bearing below said nut and arranged concentric therewith, a drive sleeve mounted in said bearing below said nut and splined to said screw sleeve, a driving member, and clutch means between the same and said drive sleeve. 7 j

10. The combination with a mining machine frame, a support'for a coal cutting device vertically adjustable thereon; of a nutsecured to said frame, a screw sleeve operating through said nut a'nd having an internal thread, a non-rotary screw threaded'into said sleeve and connected'to said su'p'port,a bearing below said nut and ar ranged concentric therewith, a drive sleeve mounted in said bearing below said nut and splined to said screw sleeve, a sprocket loosely mounted on said drive sleeve and having a clutch face, and a clutch member cooperating with 'said' clutch face and feathered upon said drivesleeve.

11. The combination with a mining machine frame, a support for a coal mining device vertically adjustable thereon, of a plurality ofdouble action screws mounted on said frame and loosely connected to said support, and a longitudinally extensible pedestal of rigid telescopic slidab-lesections for each screw connected to said frame and screw and permitting said support to be angularly disposed on said screws'while retaining its rigidity.

'12. The combination with a mining ma-. chine, a coal cutting devlce, a support there- 7 for subject to lateral thrusts imposed by the cutting device; of double action screw means .connected to the support forverticah ly adjusting thesame, and a. longitudinally extensible pedestal fassociated with said connected to the support forvertically "adjusting the same, and a telescopic pedestal partially housing said screw means and con necting said machine andsupport for bracing the screw means against lateral thrusts. 14:. The combination with a mining ma chine, a coal cutting device,a support therefor subject to lateral thrusts imposed by the action of the cutting device; of double action screw means for vertically "adjusting said support, and a sectional telescopic pedestal connecting said machine and support and bracing said screw means against said lateral thrusts.

15. Thecombination with a mining machine, a'support for a coal cutting device vertically adjustable thereon; of a; screw loosely associated with said support to permit lateral tilting of the same, a rotary screw sleeve operable upon said screw,.and a sectional telescopic pedestal connecting said machine and support and having con nection with said screw to prevent turning thereof. I I

16. The combination with a mining machine, a support for a coal cutting device.

vertically adjustable thereon; of a screw loosely depending from said support for vertically adjusting the same and to permit lateral tilting ofthe support, a rotary sleeve operable upon said screw, and a sectional telescopic pedestal connecting said machine and support and having connection with said screw to prevent turning thereof.

"17. The combination'with a mining machine, a support for a coal cutting device vertically adjustable thereon and ha'vin'g'an apertured part; 'of a screw extending through said'aperturcd part and havinga shoulder for supporting the same, a rotatable screw sleeve operable upon saidscrew, and a sectional telescopic pedestal connecting said machine and'support and having connection with "said screw to prevent turning thereof. 18. The combination with a mining mchine, a support for a coal cutting device vertically adjustable thereon, a-screw'loosely associated with said support for vertically adjusting the same, a screw sleeve operable uponsaidscrew, a sectional telescopic pedestal connecting said machine and sup chine, a support for a coal cutting device vertically adjustable thereon, a screw loosecutting device; of double action screw means ly associated'with said support for vertical ly adjusting the same, a screw 'sleeve'operable upon said screw, a sectional telescopic pedestal connecting said machine and'support and having connection with said screw to prevent turning thereof, and said pedestal sections comprising substantially-open sided rectangular members telescopically associated.

20. The combination with a mining machine frame, support for a coal cutting device; of a nut secured to said frame, a screw sleeve operating through said nut and having an internal thread, a non-rotary screw threaded into said sleeve and connected to said support, a rotary sleeve concentric with said screw sleeve and splined thereon, a clutch element feathered to'said rotary sleeve, and a cooperating driving clutch member loosely mounted on said ro tary sleeve and adapted for engagement with said clutch element.

21. The combination with a mining machine frame, a support for a coal cutting device; of a nut secured to said frame, a screw sleeve operating through said nut and having an internal thread, a non-rotary screw threaded. into said sleeve and connected to said support, a bearing below said nut and arranged concentric therewith, a drive sleeve mounted-in said bearing below said nut and splined to said screw sleeve, said drive sleeve having its upper end engaging said nut, and means for actuating said drive sleeve.

22. The combination of a mining machine frame, a support fora coal cutting device; of an elevating device including a screw for vertically adjusting said support, said screw having a supporting shoulder, and an extensible pedestal connected to said machine and including a section supported upon said shoulder.

23. The combination of a mining machine frame, a support for a coal cutting device; of an elevating device including a screw for vertically adjusting said support, said screw having a supporting shoulder, and an extensible pedestal connected to said machine and including a section supported upon said shoulder, said shoulder having a noncircular portion engaging said section to prevent turning of the screw.

2a. The combination with a mining machine frame, a support for a coal cuttingdevice, an apertured bracket carried by said support, an elevating device mounted on the frame and including a screw having its upper end extended loosely through said bracket, an extensible peoestal connected to said screw, a shouldered sleeve mounted on the upper end of said screw and extended 'hrough said apertured bracket, a coiled spring surrounding said sleeve and support ed on the shoulder thereof, and adjustable means on said screw abutting said spring.

25; In amining machine, a base, a sup port, a cutting instrumentality on said support, a'plurality of screw and nut units in terposed" between the base and support and operable to elevate and lower the support and to carry the weight thereof, and tele- 1 scopic pedestals extending between the, base and the support, said pedestals including support, said pedestals including upper sec-' tions in connection with the support and lower sections secured to the base independently of said units to transmit'to'the base independently of said units lateral thrusts exerted on the support byv the cut ting instrumentality. i I Y port, a cutting instrumentality on said support, a plurality of screw and nut units .interposed between the'base and support and operable to elevate andlowerthe support and to, carry the weight thereof, andctele 27. In a mining machine,abase,a sup" scopic pedestals extending alongside the I screw and nut units between the base and the support and partially surrounding said units, said'pedestals including uppersections in connection with the support and lower sections secured to the base independently OfxSZLlCl units to transmit to the base independently of said units lateral thrusts exertedon the support by the cutting instrumentality. i I I '28. In a mining machine, a base, a support, acutting instrumentality on said support, a plurality of screwand nut units interposed between the base and support and operable to elevate and lower the support andto carry the, Weight thereof, and=a telescopic pedestal extending between the base and the support, said pedestal comprising sections non-rotatable relative to each other, 1

the uppermost section being connected to the support andv the lowermostsection being secured-to the base independently of said units, to transmit to the :base independently of-said units lateral thrusts exerted onithe support by the cutting instrumentality;

29.1 In a miningfmachine, a base, asupport, a-cutting instrum-entality on said support, a plurality of screw 'and-nu-t units interposed between the base and support and operable to elevate and lower the support and to carry the weight thereof, and telescopic pedestals extending alongside 1 the screw: and nut units between thezbase-and the support, said pedestals comprising sections non-rotatable relative to each other, the uppermost sections being connected to the base independently of said units to transmit to the base independently of said units lateral thrusts exerted on the support by the cutting instrumentality, said uppermost sections being also connected to portions of the adjacent screw and nut units to prevent rotation thereof.

30. The combination with a supporting frame, of coal cutting mechanism mounted thereon for lateral feeding movement relatively thereto, spaced-apart individually extensible pedestals for adjustably supporting said coal cutting mechanism on said frame, means for individually adjusting the extensions of'said pedestals, and extensible means associated with each pedestal to brace the latter against lateralthrusts during lateral feeding of'said cutting mechanism into the coal.

31. The combination with a supporting frame, of a supplemental frame, a coal cutting-device mounted on said supplemental frame for lateral swinging feeding movement therewith,'double action screw mechanism for adjusting the elevation of said supplemental frame and said coal cutting device, and extensible bracing means associated with said screw mechanism to resist lateral thrusts dueto lateral feeding movement of said coal cutting device.

32. The combination with a mining ma chine frame, of coal cutting mechanism vertically adjustable thereon, a nutsecured to said frame, a screw operable through said nut and internally screw-threaded, a nonrotary screw threaded into said sleeve and connected to said coal cutting mechanism, a drive sleeve connected to said first mentioned screw, a driving member, and a clutch for connecting said driving member to said drive sleeve.

33. The combination with a supporting frame, of a coal mining device, a plurality of spaced-apart double action screw sup ports for said coal mining device, and a plurality of extensible bracing structures one for each of said screw supports and. each comprising longitudinally extensible rigid the adjacent screw support.

telescopic slidable sections co-acting with ing structure associated with said screw de means comprising a screw post for adjust 7 ing the elevation of said cutting mechanism, lateral bracing structure associated with said post and comprising a vertical guide section fixed to said frame, an upper guide section carried at the upper end of said post, and intermediate guide sections and abutments between the next adjacent guide sections for limiting the extension of the post and said bracing structure and thereby limiting the elevation of said cutting mechanism.

36. The combination with a supporting frame, of mining mechanism, means comprising a non-rotatable screw for adjusting the elevation of said mining mechanism, mechanism for preventing rotation of said screw, and resilient means for yieldingly connecting said last named mechanism to said screw.

37 The combination with a supporting frame, of mining mechanism, extensible means comprising a non-rotatable screw for adjustingthe elevation of said mining mechanism, extensible means for preventing rotation of said screw, and a spring for yield ingly holding the upper end portion of said screw connected to the upper end of said extensible rotation preventing means.

In testimony whereof I have hereunto set my handf H j v N ILS'D, LEVIN.

34. The combination with a supporting' frame, of a supplementalframe, mining mechanism mounted on said supplemental frame, means comprising an elevating screw device for adjusting the elevation of saidv supplemental frame and the mining mech'anisInthereOn, and an extensible brac- 

